Pulp density regulator



June 18, 1940. J. A. ADAMS PULP DENSITY REGULATOR Filed Sept. 7, 1937 3Sheets-Sheet 1 INV ENT OR.

June 18, 1940.

J. A. ADAMS 2,204,644

PULP DENSITY REGULATOR Filed Sept. '7, 1937 5 Sheets-Sheet I5 INVENTOR.QZ4ME S 4. A DAM 5 Patented June 18, 1946 UNITED STATES PATENT OFFICEPULP DENSITY REGULATOR Application September "I, 1937, Serial No.162,741

9Claims.

This invention relates to improvements 'in automatic pulp-densityregulators.

In certain industrial processes such as, for instance, oreconcentrating, paper making, and the like, material being treated isembodied in a pulp. This pulp usually is composed of the material in afinely divided condition carried in a liquid, usually water, withperhaps other inradients in addition.

It is important that this pulp be formed and kept at a constant densityso that the next step in the processing will be accomplished at maximumeillciency. Since the pulp usually comprises a" plurality of components,care must always be exercised in the mixing to maintain that constantdensity factor. The mixing of components to form the pulp often is acontinuous process and the present invention provides apparatus that iseffective for automatically varying a fluid component of the pulp inresponse to density variations, to maintain a substantially constantdensity.

Therefore it is an object of this invention to provide apparatus thatwill respond automatically to sustained pulp-density variations andthereby A further object is to provide apparatus that is simple andpositive in action.

A still further object is the provision of apparatus of this characterthat may be installed, optionally, in a. convenient position either at,above or below the normal pulp-level.

Stiilanother object is to provide apparatus for this purpose that willrespond in degree and time in a manner corresponding to the degree andduration of the density variation to thereby eillciently correct it.

Other objects and advantages will be more fully disclosed in thefollowing description and in the drawings wherein like parts have beensimilarly designated and in which:

Figure 1 is a vertical sectional view of apparatus built according tothis invention;

Figure 2 is a diagrammatic view of a modified arrangement of theapparatus;

- Figure 3 is a fragmentary sectional view on line 3-4 of Figure l anddrawn on a larger scale and including certain details that werepurposely omitted from Figure 1 for purposes of clarity;

Figure 4 is a wiring diagram of electrical circuits that are welladapted to be used with the apparatus;

Figure 5 is a fragmentary elevation partly in section and illustratesapparatus built according to a further modified form of the invention;and 5 Figure 6 is a fragmentary plan view, drawn to a smaller scale, ofthe apparatus shown in Figure 5.

In the drawings reference character l2 denotes a body of pulp. At l3 areshown bodies of fluid, 10 preferably water, the supply of which may berenewed at a selected rate through a conduit I4 and valves l5. Twoexpansion fluidchambers l6 and H are closed respectively by flexiblediaphragms l3 and Ma. A pair of flexible conduits I9 are in fluidconductive connection between the bodies of fluid I3 and the fluidchambers l6 and II respectively, and flexible discharge conduits connectthe respective chambers to points of fluid discharge 2 and 22respectively, which 20 are located in thebody of pulp at differentdepths below the surface.

A rigid yoke 23 connects the two diaphragms by passing around theoutside of the chambers so that, in the form shown in Figure 1, thediaphragms are held in fixed spaced relation to each other.

A partition 24 completely seals the chambers I6 and I! from each otherso that there is no flow of fluid therebetween. The yoke 23 is connectedby means of a rod 25 to a beam 26 which is fulcrumed at 21 on a standard28. On one side of the fulcrum the beam carries a slidablqcounter-weight 23 and the beam terminates in a point 30 adjacent anarcuate calibrated scale 3|. To the right of the fulcrum'the beamcarries a pair of mercury switches 32 and 33 which, as shown indiagrammatic detail in Figure 4, together serve as a motor-reversingswitch. 0n the extreme right end of the beam is a hinged member 34 whichis pivoted to the beam by means of a pin 35 and is normally held inalinement with the beam by a spring element 36.

Adjacent the right extremity of this assembly is a cam element 31mounted for rotation on a vertical shaft 33 journalled in bearings 39and 40.

. The shaft is driven by any convenient source of power, not shown,through an intermediary of a belt ll over a pulley 42 on the shaft.Adjacent its center thecain/element 31 has a symmetrical 5o concentrictrack 31a above and below which are the eccentric s 371).

, The two exp, nsion fluid chambers l6 and II are supported at theirperimeters one. pair of standards 43 in a manner to permit free movementof the diaphragms l8, and it will be understood that the conduit I4 isconnected with a source of fluid such as any common watersupply system,which is not shown.

Referring to thedetails shown in Figure 3, a grooved pulley 44 ismounted adjacent the cam element 31 and a mercury type switch is shownat 45. The switch is pivoted at 46 on a standard 41 and the left end ofthe switch is urged downwardly by means of a spring element 48. A beltor cord 49 is connected with a band 50 around the switch, and passesover the pulley 44, downwardly in close proximity to the hinged member34 and is anchored permanently to an arm 5|. The mercury'switch 45 isused 'to open and close an electrical conductor 52 which is part of anelectrical circuit shown in diagrammatic detail in Figure 4.

In the form, as shown in Figure 1, the two fluid chambers are mounted insuperposed relation so that their respective diaphragms are in axialalinement with each other and oppose each other in their movements.

In Figure 2 a modified arrangement is shown wherein the fluid chambers,which are designated as Mia and Na, are positioned in lateral relation,each with its diaphragm in a downward position as shown at lib and He.The diaphragms are connected by means of rods 25a and 251) respectively,with a fulcrumed beam 53 which in turn is connected by means of a rod 54to a second fulcrumed beam 26a which corresponds to the beam 26 inFigure l. The beam 28a is provided with a depending bar 55 adjacent andbelow its fulcrum, and a compensate ing weight 58 is adjustably carriedon the bar.

In the form shown in Figure 2 it will be noted that the fluid chambers[6a and Ila are located above the surface of the body of pulp, whereasin the preferred form shown in Figure l, the fluid chambers 16 and llare located below the surface of the pulp body I2. It will be understoodthat the various conduits are intended to be flexible so that therelative altitude of the fluid chambers, with reference to the body ofpulp, may be varied, as will be explained hereinbelow.

In Figure 4, a wiring diagram is shown which illustrates certainelectrical circuits that are well adapted to be used in connection witheither form of the apparatus.

The switches 32 and 33 each comprises a metallic conductive tube 63containing a body of mercury 81 and plugged at each end with insulatingmaterial 85. A source of power, as shown at 66, is conducted along amain conductor 6'! to switch 33 and along the main conductor 52 toswitch 32. Conductive contactors 68 pass through the respectiveinsulating plugs 65 so that when the tubes 63 are tipped in eitherdirection from the horizontal, the mercury therein will flow to thelowermost end of each tube and thereby close an electrical conductivecircuit between each tube and its respective contact point. The ourcontact points are cross-connected and are also connected with suitableleads to a motor 69 so that when the beam 26 tips in one direction,contacts will be made to operate the motor in one direction and when thebeam 25 tips the other direction the motor will be reversed.

The motor is in driving relation with a speed reducer 10, the output ofwhich is transmitted by means of a sprocket-chain H to a sprocket 12that engages a valve hand-wheel 13 by means 5 of prongs 14 to open orclose a valve 15 according to the direction of rotation of the motor.The valve 15 controls a flow denslty-aflecting fluid from a source, 16a,through a conduit 16 to the body of pulp l2. The electrically-conductivetubes 63 are carried on blocks of insulating material 11 that areattached to the beam element 26.

Operation In operation a flow of fluid is established from the fluidbodies I: through the conduits it, through the respective fluid chambersl6 and I1 and discharged through conduits 20 at different points atdifierent depths below the surface of the pulp body [2. By adjusting thesliding weight 29 on the beam element 26 a condition of stabilization ofthe beam in a normal horizontal position may be eifected. Any change inthe pulp level will affect the hydraulic pressure against each diaphragmto a like degree but any change in the pulp density will produce adiiferential pressure change on the respective diaphragms which willimpart a movement to the beam element 26 which will, in turn, actuatethe motorreversing switches 32 and 33 thereon. Movement of the beamelement 26 may be observed at its pointed end 30 with reference to thecallbrated scale 3 l.

The hinged element 34 on the right end of the beam element is normallyin close proximity to the concentric central part of the cam element ll.This normal position is clearly shown in Figures 1 and 3. When the beamelement undergoes angular movement about its pivotal axis or fulcrum 21the right end thereof will move I up or down from its normal position asthe cam element permits it to do so when the cams 3117 are rotated tothe side away from the beam.

On the next revolution of the cam element 31, either one of the cams311) will engage the hinged portion 34 of the beam element as theyrotate in the direction of the arrow D in Figure 3. This will move thehinged end 34 laterally to contact the belt or cord 49, as shown inbroken lines in Figure 3. This movement will raise the pivoted mercuryswitch 45 to its dotted line position to close the electrical conductor52 which will in turn permit power to flow from the source 68 throughthe reversing switches 32 and $3 to the motor 69 to drive it in thedirection called for by the position of the beam 28. The motor thusactuated will operate the mechanism to control the flow ofdensity-affecting fluid to the body of pulp. The operation of the camelement 31 will introduce a certain desirable factor of delay in theoperation of the density-affecting mechanism so that the resultantaction will not be too severe.

Obviously and inherently, the cam-element will intermittently move thepart 34 of the beam-element, when said beam-element is in position to becontacted by the cam.

It will be seen that due to the angular shape of the cams 31b, thefarther from normal that the hinged end 34 of the beam element 26 ismoved, the longer period of time the beam will be held in its lateralposition and the longer the circuit-breaking switch 45 will remainclosed. It will thus be apparent that the greater the variation in thepulp density the greater the automatic response will be to correct thatvariation and bring the pulp density back to normal.

Obviously the raised portions of the cam 31b 88 of the lower chamber.

vide contact periods with the beam-element of varying time duration.

In the arrangement shown in Figure 1 the flow of fluid through thechambers l6 and II will normally exert a pressure on the diaphragms l8and Ila that is above atmospheric pressure. In the arrangement shown inFigure 2 the flow through the chambers I61: and Ila becomes a syphonsystem so that a pressure below normal atmospheric is usually exerted onthe inner surface of the diaphragms Ill) and I80. In this arrangementany difierential change in the pressure exerted on the diaphragms willmove the fulcrumed beam 83 to actuate the beam element 26a ashereinabove described.

The form of the apparatus as illustrated in Figures 5 and 6 makes use ofa source of gas under pressure, that discharges simultaneously into twoopposed chambers, 88 and 8| respectively, a conduit 82 leading from thesource, not shown, to the upper chamber and a second conduit 83 leadingfromthe source to the lower chamber 8|. A rigid plate 84 is positionedbetween a flexible diaphragm closure 85 of the upper chamber and asimilar diaphragm closure A discharge conduit 81 leads to a point of gasdischarge 88 in a pulp container I21: and another discharge conduit 88leads to another point of gas discharge 98 at a different depth in thecontainer Ila.

The plate 84 is connected with a yoke 8| which in turn is pivoted to thefulcrumed beam 26 that carries the elements as above deflned. The twoexpansion chambers 88 and 8| are rigidly supported at 82 on a frame 88and it will be understood that variations in the density of the pulp I2into which' the two discharge conduits are immersed, will diflerentiallyaffect the pressures in the expansion chambers 8|! and 8| which willmove the plate 84, the yoke 8| and the Iulcrumed beam 26. The beam maygovern and be governed as hereinabove described and as illustrated inFigures 1, 3 and 4.

The diaphragms in all forms of the apparatus preferably have an area ofmany square inches so that even a small diiferential change per unit ofarea on the diaphragms will be multiplied to a very considerable totaleffective force on the mechanism actuated by the diaphragms. It will beunderstood that the movement of the diaphragms, due to a diflerentialchange in the pressure exerted thereon, may be utilized in various waysto actuate density-governing mechanism. The mechanism illustrated anddescribed herein is a typical example. It is to be further understoodthat the term pulp as herein used, means any semi-liquid or solution ormixture of liquid and solid matter. I

What I claim and desire to secure by Letters Patent is:

1. In apparatus for automatic pulp-density control, a plurality ofexpansible chambers, fluid flow means associated with said chambers anddischarging into a body of pulp at two different depths therein forexpanding and contracting said chambers according to pulp-density,variations, an element connected with a movable portion of at least oneof the chambers for movement thereby, a continuously operating memberpositioned adjacent said element for reciprocating a portion thereof indirections other than its first said movement, and a motor-operatingswitch positioned to be actuated by the reciprocating movement of theelement.

2. In apparatus for automatic pulp-density control, a pluralityof'expansible chambers, fluid flow means associated with said chambersand discharging into a body of pulp at two different depths therein forexpanding and contracting said chambers according to pulp densityvariations, an element connected with a movable portion of at least oneof the chambers for movement thereby, means adjacent the element forintermittently moving the same in a direction other than its first saidmovement, and a motoroperating switch positioned to be actuated by theintermittent movement of the element.

3. In apparatus for automatic pulp-density control, a plurality ofexpansible chambers, means for discharging flows of fluid at differentdepths in a body of pulp, said means being also connected with therespective chambers whereby they are expanded and contracted accordingto pulp-density variations, a beam-element connected with a movable partof at least one of the chambers and fulcrumed for arcuate movementthereby, means adjacent the beam-element for reciprocating a portionthereof laterally of its arcuate path, and a motor-operating switchactuated by such lateral movement according to the arcuate position ofsaid beam-element.

4. In apparatus for automatic pulp-density control, a plurality ofexpansible chambers, means for discharging flows of fluid at differentdepths in a body of pulp. said means being also connected with therespective chambers whereby they are expanded and contracted accordingto pulp-density variations, a beam-element connected with a movable partof at least one of the chambers and fulcrumed for arcuate movementthereby, means adjacent the beam-element for intermittently movingaportion thereof laterally of its arcuate path, and a motor-operatingswitch actuated by such lateral movement according to the arcuateposition of said beam-element.

5. In apparatus for automatic pulp-density control, a plurality oiexpansible chambers, means for maintaining a flow oi fluidsimultaneously through the chambers, means for discharging therespective flows of fluid at different depths in a body of pulp, wherebythe chambers are expanded or contracted according to pulpdensityvariations, 9. beam-element connected with the chambers and fulcrumedfor arcuate movement thereby, a motor-reversing switch operated by thearcuate movement of the beamelement, a cam-element positioned adjacentthe beam-element for moving a portion thereof laterally of its arcuatepath, and a motor-operating switch actuated by said lateral movement. 6.In apparatus for automatic pulp-density control, a plurality ofexpansible chambers, means for maintaining a flow of fluidsimultaneously through the chambers, means for discharging therespective flows of fluid at different depths in a body of pulp, wherebythe chambers are expanded or contracted according to pulpously throughthe chambers, means for discharging the respective flows of fluid atdifferent depths in a body of pulp, whereby the chambers are expanded orcontracted according to pulpdensity variations, a beam-element connectedwith the chambers and fulcrumed for arcuate movement thereby, a portionof said beamelement being capable of movement laterally of its arcuatepath, a motor-operating switch actuated by such lateral movement,according to v the arcuate position of said beam-element, and a tentlymoving a portion thereof laterally of its arcuate path, and amotor-operating switch actuated by said lateral movement, according tothe arcuate position of said beam-element.

9. In apparatus for automatic pulp-density control, a plurality oiexpansible chambers, means for maintaining a flow of fluid simultaneously through the chambers, means for discharging the respective flowsof fluid at different depths in a body of pulp, whereby the chambers areexpanded or contracted according to pulpdensity variations, abeam-element connected with the chambers and fulcrumed for arcuatemovement thereby, a portion of the beamelement being capable of lateralmovement, with reference to its arcuate path, a motor-operating switchactuated by such lateral movement, according to the arcuate position ofsaid beamelement, and a variable cam-element positioned adjacent thebeam-element for moving a portion thereof laterally,

JAMES A. ADAMS.

